Mark 14:38

Epistle of Polycarp to the Philippians

as the Lord has said: "The spirit truly is willing, but the flesh is weak."[47]

Cyprian Treatise IV On the Lord's Prayer

But when we ask that we may not come into temptation, we are reminded of our infirmity and weakness in that we thus ask, lest any should insolently vaunt himself, lest any should proudly and arrogantly assume anything to himself, lest any should take to himself the glory either of confession or of suffering as his own, when the Lord Himself, teaching humility, said, "Watch and pray, that ye enter not into temptation; the spirit indeed is willing, but the flesh is weak; "[72]